North Korea is threatening to cancel the forthcoming summit with the US due to ongoing military exercises between America and South Korea, according to reports.

A meeting between the two Koreas at a border village to discuss setting up military and Red Cross talks to reduce border tension and restart reunions between families separated by the Korean War has also been cancelled by Pyongyang, Yonhap News Agency said.

North Korea's Korean Central News Agency reported that Pyongyang was also questioning whether next month's summit between North Korea's Kim Jong Un and US president Donald Trump can also take place as planned.

Yonhap said the two-week military exercise between the US and South Korea started on Friday.